


Undyne selfcest

by morefishplease



Series: Comfy Fish Stories [35]
Category: Undertale (Video Game)
Genre: Erotica, F/F, Lesbian Sex, Self-cest, Vaginal Fingering
Language: English
Status: Completed
Published: 2017-04-17
Updated: 2017-04-17
Packaged: 2018-10-19 23:26:01
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 848
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10650252
Author URL: https://archiveofourown.org/users/morefishplease/pseuds/morefishplease
Summary: Undyne dreams about having sex with her identical twin.





	Undyne selfcest

While you’re out lazy Undyne manages to drag herself from bed and languorously traipse over, stand in front of the mirror, slide her panties down, peer at herself. She turns, looks at her back, lingers on her ass, which she reaches back, grabs, squeezes, lifts up, lets fall with a small smile. She tugs at her small tuft of fiery red pubic hair, traces her fingers up her abs to her breasts, cups them, squeezes them, tweaks her nipple and grins closelipped and sharktoothed at the twinge of pleasure. She reaches up, grabs her neck, tightens her fingers around her gills, feels herself puff out and suck against her hands gently, begging for oxygen. When she draws her hand back her gills are pink and exposed, faint smell like salmon.

Then she growls and steps forward through the mirror, and Undyne raises an eyebrow, peers at her grinning doppelganger, thinks to herself ‘oh, I must be dreaming.’

“But that’s no reason not to have fun,” her twin says, reaching out, laying a cold hand on Undyne’s chest. She can feel her nipples starting to harden just at the whipcrack of her twin’s voice and she laughs, low and throaty, listening to the way it sounds.

“I’ve never lucid dreamed before,” Undyne mumbles as her twin encircles her hips, digs sharp claws into her ass. It doesn’t hurt, just prickles slightly, like novocaine at the dentist. Her eyes flick back to her twins and she sees nothing but hard unfeeling gold behind those fluttering, beckoning lashes. “What the hell,” Undyne says, resigning herself, and leans in, takes her twin’s nipple into her mouth. Her twin growls with pleasure, running an initially-gentle hand through Undyne’s hair before taking hold fast, locking her head against her twin’s breast. “Mmph,” Undyne mentions, biting gently at the hard nipple, and her twin lets out a long low hiss of desire that only makes Undyne wetter.

‘Is that what I sound like?’ she thinks to herself, remembering dozens of times where you’ve coaxed noises like that, and other louder ones, from her mouth. She can feel her cheeks flushing and she starts to glance up at her twin, aching to see her own rapturous expression contorted with pleasure but all of a sudden they’re in bed and Undyne is curled up, with her twin bear-hugging her, pressing her own lovely warmth against Undyne’s back and ass and thighs. She smiles instinctively, unable to stop herself, and realizes her twin is smiling too when she feels sharp teeth rubbing oily on the back of her neck.

Her twin reaches forward and plugs her gills and time stops for a moment as Undyne feels a wave of excited pleasure race through her. She lets out a little squeak and hears her twin laugh, quiet and menacing, and a hint of delicious terror sparks in her stomach. She could still break out – she thinks, but her twin reaches forward with her other hand, traces her way down her stomach, down her abdomen, tangles in her pubic hair, lays one blazing finger atop Undyne and Undyne shudders, presses herself eagerly against the finger, hears her twin laugh again, thick with lust.

“Tell me what you want,” her twin growls into her ear, transferring her hand from Undyne’s gills to her breast, squeezing almost too hard, tracing her thumb roughly over Undyne’s nipple. Undyne can barely think straight although she isn’t sure whether to attribute it to the lack of oxygen or to her current arousal. She thrusts against her twin again and hears a displeased hiss as she withdraws her slick finger. “Uh uh,” her twin whispers. “Tell me what you want,” she repeats.

“I want you to fuck me,” she murmurs, trading a loaded glance with her best bedroom eyes reflected back at her.

“More specific,” her twin says, grin widening, and Undyne rolls her eyes. Even her own subconscious is sassy, she thinks.

“I want you to rub my clit,” she begins, “and then choke me while you stick your finger – mmph!”

Her twin has stuck her finger into Undyne’s mouth and Undyne splutters for a moment before running her tongue over it delicately. The finger is thick with Undyne’s juices and tastes vaguely like honey, and she sucks on it rapturously before it’s withdrawn from her mouth with a wet pop and begins its achingly slow journey down her body, leaving a wet trail down her chest, detouring over one nipple…

As it reaches her groin Undyne lets out a throaty moan of anticipation, and her twin inches forward another centimeter –

“Hey, I’m home! I went and got us – oh, you’re still asleep?”

“NGAHHH - !” Undyne’s eyes burst open at the sound of your voice, and she rises out of the covers, glares at you, who are too surprised by the sudden motion to speak. You watch Undyne feel at herself and pull her hand back dripping wet, and then your eyes meet. Undyne licks her lips, breaks into a lustful grin, and you manage to drop the groceries before Undyne tackles you to the floor.

**Author's Note:**

> More fetish stuff, in this case selfcest. I had a hard time coming up with a good way to fit this into the continuity I was working on and I'd almost resigned myself to doing a swap thing or whatever and just letting it stand alone when I figured it could be a dream. I've never lucid dreamt so I imagine this might be a little inaccurate but it's whatever, I'm okay with it.
> 
> I debated for a while about adding a comma to the first sentence, before 'lazy,' but in the end I kept it as it is because the comma slows down the reader as they go through the line, which makes them more grounded. Without the comma you run through it fast at first and then double back and try and decide what it meant, which is obvious after you think about it, but it isn't grammatically correct and pedants might turn their noses up at it. For me the feel of a story is a lot more important than following the rules, and I wanted to make the dream-state Undyne is in obvious, so I use a little more poetic language here than I typically do.


End file.
